MADISON - Gov. Scott Walker — who mounted a brief bid for the presidency just months after winning re-election in 2014 — pledged Monday to serve a full four years if he's elected to a third term in November.

The GOP governor also suggested Missouri's Republican governor should resign; sidestepped saying whether he agreed with former FBI Director James Comey's comments that the president is unfit to serve; and backed the idea of setting up military training posts along Mexico's border.

"Tommy Thompson told me if not once, a thousand times, his worst day as governor was better than his best day in the cabinet, so I can unequivocally without hesitation tell you I will never willingly leave the role as governor through this next coming term," Walker said.

Walker said Thompson — who left office in 2001 in his fourth term to become President George W. Bush's health secretary — had "pounded into my head" that serving as governor is better than working for a president.

"You can get much, much, much more done as a governor and it's much, much, much more fulfilling being a governor than it is being in the cabinet," Walker said.

Walker's comment was similar to one he made just weeks before he was re-elected in 2014. During a debate with Democratic opponent Mary Burke that October, Walker said: "My plan is if the people of the state of Wisconsin elect me on November 4 is to be here for four years."

Within a few months, he began exploring and then pursuing his bid for the presidency, which he abandoned in September 2015.

"Governor Walker has already demonstrated that Wisconsin voters cannot take him at his word when it comes to his commitment to this state," said Joe Zepecki, a Democratic consultant who helped run Burke's campaign.

Walker signaled he believed it was time for Missouri Gov. Eric Greitens to go. Walker campaigned for Greitens, but the Missouri governor has since been urged to resign amid a sex scandal and a felony charge for invasion of privacy for taking a picture of a nude woman without her consent.

"If those reports are accurate, and it seems like they keep re-affirming those, I don't know how someone stays in that position," Walker said. "I just think for the citizens of that state it's difficult if not impossible for him to govern."

As he has before, Walker said he would support sending Wisconsin National Guard troops to the Mexican border if Trump's administration asks for the state's help. He also said he thought it was "logical" for the country to install military training posts along the nation's borders.

Meanwhile Monday, the governor also signed Assembly Bill 691, which bans buyers who owe back property taxes or building code fines from buying foreclosed properties at sheriff's sales.

Walker also signed Assembly Bill 748, which would generally bar local governments from setting tougher employment standards than those in state law. Racine County Executive Jonathan Delagrave sought unsuccessfully to stop the legislation, saying it could hurt efforts to help local people get jobs at the massive flat-screen plant there being planned by Foxconn Technology Group.

Senate Bill 58 creates a specific felony for carjacking with fines of up to $50,000 and prison sentences of up to 15 years. The proposal also would increase penalties for repeated auto theft to up to $25,000 in fines or up to 12 years and 6 months in prison.

Senate Bill 55 increases the mandatory penalty for murder, second-degree homicide and certain other repeat violent offenses to five years in prison, up from the current minimum of three years and six months.

Senate Bill 56 toughens penalties on certain violent offenders who are banned from keeping a gun and do so anyway.

Sen. Leah Vukmir (R-Brookfield) said her four measures made sense even if they could raise costs for taxpayers.

"Wisconsinites deserve to feel safe," said Vukmir, who is running in the GOP primary for U.S. Senate.